Problem: $ { \left[\begin{array}{r}{2} \\ {2} \\ {-1}\end{array}\right]+\left[\begin{array}{r}{-2} \\ {0} \\ {-2}\end{array}\right] = {?} } $
Answer: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{r}{2}+{-2} \\ {2}+{0} \\ {-1}+{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{0} \\ {2} \\ {-3}\end{array}\right]}$